3 NaHSO3 (aq) + NaOH (aq) + 2 KMnO4 (aq) → 2 Na2SO4 (aq) + 2 MnO2 (s) + K2SO4 (aq) + 2 H2O (l)
This is an oxidation-reduction (redox) reaction:
2 MnVII + 6 e- → 2 MnIV (reduction)
3 SIV - 6 e- → 3 SVI (oxidation)
KMnO4 is an oxidizing agent, NaHSO3 is a reducing agent.
This is a precipitation reaction: MnO2 is the formed precipitate.